The present invention relates to a process for servicing a number of mutually adjacent spinning positions of an open-end spinning machine by means of a servicing apparatus for carrying out this process.
Servicing work becomes necessary again and again on open-end spinning machines, and is carried out either in rotation or according to need. For example, the yarn has to be strung up at the beginning of the spinning process or after a yarn break. In a further servicing process, the piecings in the yarn can also be eliminated by a knotting process. Furthermore, the open-end spinning machine has to be serviced as regards bobbin changes and cleaning of the spinning unit, particularly the spinning rotor.
In order to be able to carry out such servicing, various preparatory work has to be undertaken, in order to prepare the spinning position for the servicing process proper. Thus it is necessary to bring the servicing apparatus into the required working position.
An apparatus is known in which a call device built as a yarn monitor is arranged on the machine frame which forms the stationary part of a servicing apparatus, this device causing, by means of a connection switch device, travel of a unit which can be moved by a travel drive along the machine (West German Offenlegungsschrift No. 2,350,840), where it can be stopped by a disconnection switch device brought into a readiness position by the yarn monitor. This unit serves to prepare for piecing of a yarn break. A second unit, which then pieces the broken yarn, is called up by the first unit after the first unit has concluded its work. In the present state of the art, calling is thus effected by the devices monitoring or controlling the machine, which devices can also be released, in fact, by an operator. Such a solution has in practice not been found to be economical, since the cost of materials and time for it is not justified by the saving in manpower which can be achieved. Furthermore, an automatically operating servicing equipment of this type makes possible only a rigid working program, so that either the fault is respectively eliminated at the next adjacent spinning position, or else faults are eliminated in the order in which they occur. In this manner, however, long down-times at many inoperative spinning positions, and unnecessary path times for the servicing apparatus, cannot be avoided. When servicing, e.g., yarn piecing, fails, a manual servicing is necessary after two or three fruitless attempts, so that the operator has to go to the spinning position concerned. Thus, an automatic servicing apparatus cannot completely replace manual servicing.
According to another known process (West German Auslegeschrift No. 2,351,458), to work stages for servicing are divided, so that work requiring special precision is carried out automatically, while the operator carries out the work stages which can easily be carried out manually but however would require complicated apparatus with considerable cost in an automatic version. Thus in the known apparatus the servicing apparatus is brought by hand into the required working position, since a call device is not provided. Then, manually, the bobbin is lifted from the winding roller, the yarn required for piecing is drawn from the bobbin, the yarn is brought to the exact stringup length by parting, the bobbin is deposited on the support, the yarn is deflected via a yarn disposal element, and the yarn end is partially introduced into the spinning unit of the spinning position. Only after these preparatory steps can the servicing proper, namely the release of the yarn which is sucked into the spinning unit, and the lowering of the bobbin which thus causes the resumption of yarn takeoff, be automatically carried out.
In a similar manner, before other servicing processes preparatory work is carried out to prepare the spinning position for the servicing, the preparatory work differing according to the servicing to be undertaken.
However, in this known state of the art, the servicing apparatus has to be make ready by hand, in that the operator, when a yarn break occurs, fetches the servicing apparatus or always takes it along with him.